Contagious equine metritis: A 2020 vision on control of a notifiable equine disease in the United Kingdom.

This article discusses the history, control and the proposal to change the notifiable disease status of Contagious Equine Metritis (CEM), a sexually transmitted disease in horses. The authorities propose shifting some responsibilities for handling the disease to the owners and veterinary practitioners. This step is seen as a significant change in managing a treatable notifiable disease.

Background and History

• The initial outbreak of CEM in Newmarket in 1977 led to extensive research and the identification of the disease’s causative agent, Taylorella equigenitalis. Following its identification, significant efforts have been made to control the disease, especially in the Thoroughbred sector, using the Horserace Betting Levy Board’s (HBLB) Code of Practice for Breeders.
• The Ministry of Agriculture, Fisheries and Food (MAFF; now Defra) made the suspected isolation of the causative agent in a laboratory notifiable in Great Britain via the Infectious Diseases of Horses Order 1987.
• The purpose of this provision was to provide evidence to importing countries that the UK was free of the disease.
• It provided MAFF with the powers to investigate the disease and imposed animal movement restrictions in certain circumstances.

Status of CEM In Recent Years

• Over the past 15 years, there has been a low occurrence of the disease, with only 10 CEM notifications involving 13 animals made by Defra to the World Organisation for Animal Health (OIE) since 2004.
• Most positive CEM cases were individual, non-Thoroughbred horses, mostly imported from mainland Europe and detected whilst in pre-export quarantine.
• The last isolation of CEM in the UK was done in 2012, involving four confirmed cases.

Proposals for Changes to CEM’s Status

• In 2014, Defra suggested to eliminate CEM’s notifiable disease status because the condition can be controlled through good hygiene practices and veterinary treatment.
• This proposal was challenged by the equine industry with the rationale that removing CEM from the notifiable disease list could negatively impact the UK’s valuable export market in Thoroughbred horses.
• Following discussions with the industry, Defra agreed to keep CEM as a notifiable disease, but also suggested sharing the disease’s control responsibility between Defra and the equine industry.
• In this model, the owner of a suspect animal would have the choice between having the outbreak investigated and treated by a listed equine veterinary surgeon experienced in equine reproduction and compliant with the HBLB Code of Practice or having the case dealt with by the Animal and Plant Health Agency (APHA), which could impose movement restrictions.

Implementing the New System

• The proposed changes, termed a ‘pilot scheme,’ were launched on February 1, 2018, and will be reviewed after two years or after the next outbreak of the disease.
• Since the introduction of the scheme, the owners of suspected or confirmed cases can decide to have the case managed by an approved vet without the involvement of APHA and without movement restrictions, provided they comply with the HBLB Code of Practice.
• This scheme introduces a significant change in how a treatable notifiable disease should be managed, leaving the Government with ultimate control responsibility, while more detailed procedures are carried out by suitably experienced and listed equine veterinary practitioners.